<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>
    <li>123123</li>
</body>
<script>
    var num = new Number(1);
    console.dir(num);

    // li -> HTMLLIElement -> HTMLElement -> Element -> Node -> EventTarget -> Object ->null
    // var li = document.querySelector("li");
    // console.dir(li);

    // console.log(li instanceof HTMLLIElement);
    // console.log(li instanceof HTMLElement);
    // console.log(li instanceof Element);
    // console.log(li instanceof Node);
    // console.log(li instanceof EventTarget);

    // console.dir(EventTarget);
    var o = new EventTarget();
    console.log(o);


    o.addEventListener("heihei", function () {
        console.log("你好!");
    })

    var e = new Event("heihei");
    o.dispatchEvent(e);


</script>

</html>